Mechanical Behaviour of Gas Nitrided Ti6Al4V Bars Produced by Selective Laser Melting

2016 ◽  
Vol 704 ◽  
pp. 225-234 ◽  
Author(s):  
Peter Franz ◽  
Aamir Mukhtar ◽  
Warwick Downing ◽  
Graeme Smith ◽  
Ben Jackson
Keyword(s):  
Heat Treatment ◽  
Selective Laser Melting ◽  
Nitrided Layer ◽  
Xrd Analysis ◽  
Compound Layer ◽  
Processing Parameters ◽  
Heat Treatments ◽  
Laser Melting ◽  
Gas Nitriding ◽  
Heat Treated

Gas atomized Ti-6Al-4V (Ti64) alloy powder was used to prepare distinct designed geometries with different properties by selective laser melting (SLM). Several heat treatments were investigated to find suitable processing parameters to strengthen (specially to harden) these parts for different applications. The results showed significant differences between tabulated results for heat treated billet Ti64 and SLM produced Ti64 parts, while certain mechanical properties of SLM Ti64 parts could be improved by different heat treatments using different processing parameters. Most heat treatments performed followed the trends of a reduction in tensile strength while improving ductility compared with untreated SLM Ti64 parts.Gas nitriding [GN] (diffusion-based thermo-chemical treatment) has been combined with a selected heat treatment for interstitial hardening. Heat treatment was performed below β-transus temperature using minimum flow of nitrogen gas with a controlled low pressure. The surface of the SLM produced Ti64 parts after gas nitriding showed TiN and Ti2N phases (“compound layer”, XRD analysis) and α (N) – Ti diffusion zones as well as high values of micro-hardness as compared to untreated SLM produced Ti64 parts. The microhardness profiles on cross section of the gas nitrided SLM produced samples gave information about the i) microhardness behaviour of the material, and ii) thickness of the nitrided layer, which was investigated using energy dispersive spectroscopy (EDS) and x-ray elemental analysis. Tensile properties of the gas nitrided Ti64 bars produced by SLM under different conditions were also reported.

Influence of Heat Treatment on Microstructure and Mechanical Properties of Selective Laser Melted TiAl6V4 Alloy

2018 ◽  
Vol 284 ◽  
pp. 615-620 ◽  
Author(s):  
R.M. Baitimerov ◽  
P.A. Lykov ◽  
L.V. Radionova
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Selective Laser Melting ◽  
Room Temperature ◽  
Base Alloy ◽  
Tensile Tests ◽  
Heat Treatments ◽  
Laser Melting ◽  
Microstructure And Mechanical Properties ◽  
Treatment Procedures

TiAl6V4 titanium base alloy is widely used in aerospace and medical industries. Specimens for tensile tests from TiAl6V4 with porosity less than 0.5% was fabricated by selective laser melting (SLM). Specimens were treated using two heat treatment procedures, third batch of specimens was tested in as-fabricated statement after machining. Tensile tests were carried out at room temperature. Microstructure and mechanical properties of SLM fabricated TiAl6V4 after different heat treatments were investigated.

Additive manufacturing of CMSX-4 Ni-base superalloy by selective laser melting: Influence of processing parameters and heat treatment

2019 ◽  
Vol 30 ◽  
pp. 100874 ◽  
Author(s):  
Inmaculada Lopez-Galilea ◽  
Benjamin Ruttert ◽  
Junyang He ◽  
Thomas Hammerschmidt ◽  
Ralf Drautz ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Additive Manufacturing ◽  
Selective Laser Melting ◽  
Processing Parameters ◽  
Laser Melting ◽  
Base Superalloy

scholarly journals Effects of Heat Treatment of Selective Laser Melting Printed Ti-6Al-4V Specimens on Surface Texture Parameters and Cell Attachment

2021 ◽  
Vol 11 (5) ◽  
pp. 2234
Author(s):  
Pei-Wen Peng ◽  
Jen-Chang Yang ◽  
Wei-Fang Lee ◽  
Chih-Yuan Fang ◽  
Chun-Ming Chang ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Selective Laser Melting ◽  
Surface Texture ◽  
Large Scale ◽  
Cell Attachment ◽  
Characteristic Length ◽  
Laser Melting ◽  
Heat Treated ◽  
Texture Parameters ◽  
Areal Surface

Selective laser melting (SLM) is extensively used for fabricating metallic biomedical products. After 3D printing, it is almost always advisable to apply a heat treatment to release the internal tensions or optimize the mechanical properties of the printed parts. The aim of this paper is to investigate the effects of heat treatment of SLM printed Ti-6Al-4V (Ti64) circular specimens on the areal surface texture parameters and cell attachment. Areal surface texture parameters, including the arithmetic mean height (Sa), root-mean-square height (Sq), skewness (Ssk), and kurtosis (Sku) were characterized. In addition, wavelet-based multi-resolution analysis was applied to investigate the characteristic length scales of untreated and heat-treated Ti64 specimens. In this study, the vertical distance between the highest and lowest position of cell attachment for each sampling area was defined as DH. Results showed that an increase in the periodic characteristic length scale was primarily due to the formation of large-scale aggregations of Ti64 metal powder particles on the heat-treated surface. In addition, MG-63 cells preferred lying in concave hollows; in heat-treated specimens, values of DH statistically significantly decreased from 31.6 ± 4.2 to 8.8 ± 2.8 μm, while Sku decreased from 3.3 ± 1.4 to 2.6 ± 0.6, indicating a strong influence of Sku on cell attachment.

Influence of Post Heat Treatment on Microstructure and Mechanical Property of Ti6Al4V Parts Produced by Selective Laser Melting

2017 ◽  
Vol 898 ◽  
pp. 1312-1317 ◽  
Author(s):  
Hong Yu Ding ◽  
Pei Kun Qiu ◽  
Yuan Fei Han ◽  
Zhong Gang Sun ◽  
Jie Huang ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Selective Laser Melting ◽  
Room Temperature ◽  
Preliminary Investigation ◽  
Side View ◽  
Laser Melting ◽  
Post Heat Treatment ◽  
Heat Treated ◽  
Top View ◽  
Microstructure And Mechanical Property

A preliminary investigation of the post heat treatment for Ti6Al4V tensile specimens fabricated via selective laser melting (SLM) are reported. The resultant microstructure and mechanical behavior at room temperature, normal and parallel to the building direction, was investigated in detail. Moreover, the as-prepared samples were compared with the samples post heat treated at 600°C~800°C for 2 h. It was found that the SLM fabricated samples consisted of long columnar original β grains together with parallel acicular α' martensitic structure dominated in the β matrix, which was observed in the side view, and fully equaixed β grains pattern in the top view. The post heat treatment did not completely disrupt the layered structure, but leading to the acicular α' martensites decomposing into α platelets distributed in a metastable β matrix. Ultimate tensile strength and elongation were analyzed and explained based on the microstructure evolution. After post heat treatment, an increase in elongation was observed for the tensile samples, inducing more ductile like morphology after fracture.

scholarly journals Microstructure and Mechanical Properties of Al–(12-20)Si Bi-Material Fabricated by Selective Laser Melting

Materials ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2126 ◽  
Author(s):  
Shikai Zhang ◽  
Pan Ma ◽  
Yandong Jia ◽  
Zhishui Yu ◽  
Rathinavelu Sokkalingam ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Tensile Strength ◽  
Selective Laser Melting ◽  
Dimensional Accuracy ◽  
High Dimensional ◽  
Laser Melting ◽  
Geometrical Complexity ◽  
Microstructure And Mechanical Properties ◽  
Heat Treated

In this study, a combination of Al–12Si and Al–20Si (Al–(12-20)Si) alloys was fabricated by selective laser melting (SLM) as a result of increased component requirements such as geometrical complexity and high dimensional accuracy. The microstructure and mechanical properties of the SLM Al–(12-20)Si in as-produced as well as in heat-treated conditions were investigated. The Al–(12-20)Si interface was in the as-built condition and it gradually became blurry until it disappeared after heat treatment at 673 K for 6 h. This Al–(12-20)Si bi-material displayed excellent mechanical properties. The hardness of the Al–20Si alloy side was significantly higher than that of the Al–12Si alloy side and the disparity between both sides gradually decreased and tended to be consistent after heat treatment at 673 K for 6 h. The tensile strength and elongation of the Al–(12-20Si) bi-material lies in between the Al–12Si and Al–20Si alloys and fracture occurs in the Al–20Si side. The present results provide new insights into the fabrication of bi-materials using SLM.

scholarly journals Effect of Heat Treatment on Microstructure and Mechanical Properties of a Selective Laser Melting Processed Ni-Based Superalloy GTD222

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3668
Author(s):  
Tian Xia ◽  
Rui Wang ◽  
Zhongnan Bi ◽  
Guoliang Zhu ◽  
Qingbiao Tan ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Additive Manufacturing ◽  
Selective Laser Melting ◽  
Treatment Process ◽  
Heat Treatment Process ◽  
Laser Melting ◽  
Microstructure Characteristics ◽  
Microstructure And Mechanical Properties ◽  
Heat Treated

Additive manufacturing (AM) of nickel-based superalloys is of high interest for application in complex hot end parts. However, it has been widely suggested that the microstructure-properties of the additive manufacturing processed superalloys are not yet fully clear. In this study, the GTD222, an important superalloy for high-temperature hot-end part, were prepared using selective laser melting and then subjected to heat treatment. The microstructure evolution of the GTD222 was investigated and the mechanical properties of heat treated GTD222 were tested. The results have shown that the grain size of the heat treated GTD222 was close to its as-built counterparts. Meanwhile, a large amount of γ’ and nano-scaled carbides were precipitated in the heat treated GTD222. The microstructure characteristics implied that the higher strength of the heat treated GTD222 can be attributed to the γ’ and nano-scaled carbides. This study provides essential microstructure and mechanical properties information for optimizing the heat treatment process of the AM processed GTD222.

scholarly journals Effect of Heat Treatment Condition on Microstructural and Mechanical Anisotropies of Selective Laser Melted Maraging 18Ni-300 Steel

Metals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 410 ◽  
Author(s):  
Dohyung Kim ◽  
Taehwan Kim ◽  
Kyeongsik Ha ◽  
Jeong-Jung Oak ◽  
Jong Bae Jeon ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Tensile Strength ◽  
Selective Laser Melting ◽  
Solution Heat Treatment ◽  
Laser Scanning ◽  
Solution Treatment ◽  
Heat Treatments ◽  
Mechanical Anisotropy ◽  
Laser Melting ◽  
Maraging Steels

18Ni-300 maraging steel produced by the selective laser melting (SLM) process has a unique microstructure that is different from that of the same alloy processed by conventional methods. In this paper, maraging steels were fabricated by the selective laser melting process and their microstructures and mechanical properties were investigated in terms of post heat treatment conditions. Moreover, the effect of different heat treatments on the mechanical anisotropy was studied in detail. The micro Vickers hardness in the as-built state was around 340 Hv and could be increased to approximately 600 Hv by aging heat treatments. It was found that the solution heat treatment was not necessary to obtain a fully hardened state. From tensile tests of the maraging steels heat treated with different conditions, it was found that the highest strength was achieved by aging and solution treatment (ST) temperatures lower than the commonly used temperatures. In the direction parallel to the laser scanning, the highest ultimate tensile strength was obtained when 450 °C aging was done without solution heat treatment. In the other two directions tested, i.e., directions normal to the building and 45 degrees to the laser scanning direction, the highest tensile strength was obtained when aging was done at 450 °C after 750 °C solution treatment.

A research on the effect of retrogression and re-aging heat treatment on hot tensile properties of AA7075 aluminum alloys

2021 ◽  
pp. 1-23
Author(s):  
Talha Sunar ◽  
Dursun Ozyurek
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Ductile Fracture ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Xrd Analysis ◽  
Tensile Tests ◽  
Heat Treatments ◽  
Tensile Behaviour ◽  
Heat Treated

Abstract Aluminium alloys are preferred in most industries due to the functional properties they provide. It is known that alloys that can be processed with heat treatments shows better mechanical properties. 7xxx series alloys can be processed vi heat treatments and are often used in environmental conditions such as extreme temperatures and corrosive environments. Corrosive sensitivities such as stress corrosion cracking (SCC) can be observed with the effect of working conditions. It is known that retrogression and re-aging (RRA) heat treatment provide corrosion resistance and decrease the SCC velocity. The purpose of this study is to examine the tensile behaviour of annealed and retrogression-re-aging (RRA) heat treated AA7075 alloys at elevated temperatures. The mechanical properties of the alloys were investigated by conducting tensile tests at room temperature (RT), 100, 200, and 300°C. Hardness tests were performed at room temperature on the samples which were taken from tensile test specimens after tensile tests. The potential effects of test temperature on mechanical and microstructural properties were examined. The annealed and RRA heat treated alloys were characterized by scanning electron microscope (SEM), and X-ray diffraction (XRD) analysis. As a result, an increase in strength and hardness of the RRA treated AA7075 alloys was observed. Ductility of the RRA alloy was lower compared to the annealed AA7075 alloy. Fracture surface examinations showed that there was a semi-ductile fracture below 200°C and ductile fracture at temperatures of 200 and 300°C. Ductility was observed to increase with increasing temperature.

Microstructural and Mechanical Properties of Selective Laser Melted Al 4047

2015 ◽  
Vol 752-753 ◽  
pp. 485-490 ◽  
Author(s):  
Shafaqat Siddique ◽  
Eric Wycisk ◽  
Gerrit Frieling ◽  
Claus Emmelmann ◽  
Frank Walther
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Selective Laser Melting ◽  
Process Parameters ◽  
Processing Parameters ◽  
Complex Geometries ◽  
Optimal Parameters ◽  
Post Processing ◽  
Laser Melting ◽  
Process Cost

Selective laser melting (SLM) has been recognized as a pertinent process for manufacturing of complex geometries. Al 4047 has been manufactured in this study with different processing parameters of the SLM process to obtain the optimal parameters suitable for required applications, as well as to determine the effect of these parameters and post-processing heat treatment on mechanical properties. A unique Al-Si eutectic microstructure is obtained with Al dendrites growing in the scanning direction. Mechanical properties of the SLM manufactured Al 4047 are at par with those of conventionally manufactured alloy. These properties can be varied by changing the SLM process parameters which can help controlling the process cost depending upon required mechanical properties.

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